Mass spectrometers and other systems for chemical and particle analysis are utilized for measurement of the concentration of analytes or the detection and measurement of contaminants and trace additives in solutions and gases. One type of mass spectrometer is an inductively coupled plasma mass spectrometer (ICP-MS). ICPMS is a practical technique for trace and ultratrace elemental analysis. The measurements made by ICP-MS are utilized to determine and manage the quality of process solutions. Ultrapure water (UPW), dilute hydrofluoric acid (HF), and standard industry clean formulations SC1 (Standard Clean 1, ammonium hydroxide and hydrogen peroxide in water) and SC2 (hydrochloric acid and hydrogen peroxide in water) are examples of solutions that are routinely analyzed. Quick and accurate analysis in these and other industrial processes can result in the early detection of contamination problems, better control of process chemistry, and ultimately lead to higher yields and less product variation.
While many advances have been made in instrumentation, the introduction of a sample to the plasma continues to be a problematic area. Specifically, because of elemental quantification requirements and ultimate detection limits in elemental analysis, the collisions that break the molecular species into their elemental or individual atomic components are much more energetic (“harder”) through the creation of more highly accelerated ions (with higher energy). For this reason, an inductively coupled plasma (ICP) ionization source is often preferred for molecular ionization and disintegration, due to its ability to completely break molecules into their elemental components. An ICP source works generally by coupling radio frequency (RF) energy into a gas stream containing the nebulized liquid or gas sample with the result that the sample is immediately heated to several thousand degrees. Molecules break apart at these temperatures and collision energies leaving only elemental ions. The plasma source generates a substantial amount of heat within the ICP MS torch during molecular breakdown. The heat generated from the plasma source often causes damage to injectors. Referring to FIG. 1, an injector 100, illustrating an end portion 102 by that has been eroded by exposure to plasma heat is shown. Disadvantageously, this erosion results in unusable injectors, and requires frequent replacement of injector bodies, or injector assemblies.
Therefore, it would be desirable to provide an apparatus which prevented heat erosion of an injector during molecular ionization and disintegration using a plasma source or other extremely high heat source.